Daphnia Lab Report

The Effect of Temperature and Epinephrine on The Heart Rate of Daphnia Leslie Orzetti-Gollhofer
Gaby Macias

INTRODUCTIONThe Daphnia is a Crustacean other known as the water flea. It lives in small bodies of freshwater. The Daphnia is ectothermic, meaning it controls its body temperature through external means. With this experiment we experienced first hand what the effect temperature has on a Daphnia’s heart rate. We also experimented what effect epinephrine has on a Daphnia’s heart rate. HYPOTHESIS

If we add hot water, then the Daphnia’s heart rate will increase. If we add cold water, the Daphnia’s heart rate will decrease. If we add epinephrine, then the heart rate will increase.
MATERIALS AND METHODSA pipet was used to place the Daphnia with water on a glass slide. The slide was then placed under a glass microscope to be observed for the experiment. A tally counter was used to count the heart rates of the Daphnia when it was placed in warm water, under ice and in epinephrine. RESULTS

When we experimented what the effect temperature has on the Daphnia’s heart rate, we started with an average control of 64 beats in 15 seconds. After placing the Daphnia in warm water the average heart rate went up to an average of 72 beats in 15 seconds, with an average increase of 12.5%. When we placed the Daphnia over ice the average heart rate decreased to an average of 43 beats in 15 seconds, with an average decrease of 33%. When we experimented what the effect of epinephrine has on the Daphnia’s heart rate, we started with an average control of 73 beats in 15 seconds before adding epinephrine. When the epinephrine was added to our experiment the average heart rate increased to 83 beats in 15 seconds., with an average of 14%. After the epinephrine was diluted from the slide the average heart rate returned to an average of 78 beats in 15 seconds, with a decrease of 7% from the heart rate with epinephrine. DISCUSSION